1 files changed, 269 insertions, 0 deletions
diff --git a/src/net/udpsock_posix.go b/src/net/udpsock_posix.go
new file mode 100644
index 0000000..6544397
--- /dev/null
+++ b/src/net/udpsock_posix.go
@@ -0,0 +1,269 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || windows
+
+package net
+
+import (
+	"context"
+	"net/netip"
+	"syscall"
+)
+
+func sockaddrToUDP(sa syscall.Sockaddr) Addr {
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
+	case *syscall.SockaddrInet6:
+		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
+	}
+	return nil
+}
+
+func (a *UDPAddr) family() int {
+	if a == nil || len(a.IP) <= IPv4len {
+		return syscall.AF_INET
+	}
+	if a.IP.To4() != nil {
+		return syscall.AF_INET
+	}
+	return syscall.AF_INET6
+}
+
+func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
+	if a == nil {
+		return nil, nil
+	}
+	return ipToSockaddr(family, a.IP, a.Port, a.Zone)
+}
+
+func (a *UDPAddr) toLocal(net string) sockaddr {
+	return &UDPAddr{loopbackIP(net), a.Port, a.Zone}
+}
+
+func (c *UDPConn) readFrom(b []byte, addr *UDPAddr) (int, *UDPAddr, error) {
+	var n int
+	var err error
+	switch c.fd.family {
+	case syscall.AF_INET:
+		var from syscall.SockaddrInet4
+		n, err = c.fd.readFromInet4(b, &from)
+		if err == nil {
+			ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 4 bytes
+			*addr = UDPAddr{IP: ip[:], Port: from.Port}
+		}
+	case syscall.AF_INET6:
+		var from syscall.SockaddrInet6
+		n, err = c.fd.readFromInet6(b, &from)
+		if err == nil {
+			ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 16 bytes
+			*addr = UDPAddr{IP: ip[:], Port: from.Port, Zone: zoneCache.name(int(from.ZoneId))}
+		}
+	}
+	if err != nil {
+		// No sockaddr, so don't return UDPAddr.
+		addr = nil
+	}
+	return n, addr, err
+}
+
+func (c *UDPConn) readFromAddrPort(b []byte) (n int, addr netip.AddrPort, err error) {
+	var ip netip.Addr
+	var port int
+	switch c.fd.family {
+	case syscall.AF_INET:
+		var from syscall.SockaddrInet4
+		n, err = c.fd.readFromInet4(b, &from)
+		if err == nil {
+			ip = netip.AddrFrom4(from.Addr)
+			port = from.Port
+		}
+	case syscall.AF_INET6:
+		var from syscall.SockaddrInet6
+		n, err = c.fd.readFromInet6(b, &from)
+		if err == nil {
+			ip = netip.AddrFrom16(from.Addr).WithZone(zoneCache.name(int(from.ZoneId)))
+			port = from.Port
+		}
+	}
+	if err == nil {
+		addr = netip.AddrPortFrom(ip, uint16(port))
+	}
+	return n, addr, err
+}
+
+func (c *UDPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr netip.AddrPort, err error) {
+	switch c.fd.family {
+	case syscall.AF_INET:
+		var sa syscall.SockaddrInet4
+		n, oobn, flags, err = c.fd.readMsgInet4(b, oob, 0, &sa)
+		ip := netip.AddrFrom4(sa.Addr)
+		addr = netip.AddrPortFrom(ip, uint16(sa.Port))
+	case syscall.AF_INET6:
+		var sa syscall.SockaddrInet6
+		n, oobn, flags, err = c.fd.readMsgInet6(b, oob, 0, &sa)
+		ip := netip.AddrFrom16(sa.Addr).WithZone(zoneCache.name(int(sa.ZoneId)))
+		addr = netip.AddrPortFrom(ip, uint16(sa.Port))
+	}
+	return
+}
+
+func (c *UDPConn) writeTo(b []byte, addr *UDPAddr) (int, error) {
+	if c.fd.isConnected {
+		return 0, ErrWriteToConnected
+	}
+	if addr == nil {
+		return 0, errMissingAddress
+	}
+
+	switch c.fd.family {
+	case syscall.AF_INET:
+		sa, err := ipToSockaddrInet4(addr.IP, addr.Port)
+		if err != nil {
+			return 0, err
+		}
+		return c.fd.writeToInet4(b, &sa)
+	case syscall.AF_INET6:
+		sa, err := ipToSockaddrInet6(addr.IP, addr.Port, addr.Zone)
+		if err != nil {
+			return 0, err
+		}
+		return c.fd.writeToInet6(b, &sa)
+	default:
+		return 0, &AddrError{Err: "invalid address family", Addr: addr.IP.String()}
+	}
+}
+
+func (c *UDPConn) writeToAddrPort(b []byte, addr netip.AddrPort) (int, error) {
+	if c.fd.isConnected {
+		return 0, ErrWriteToConnected
+	}
+	if !addr.IsValid() {
+		return 0, errMissingAddress
+	}
+
+	switch c.fd.family {
+	case syscall.AF_INET:
+		sa, err := addrPortToSockaddrInet4(addr)
+		if err != nil {
+			return 0, err
+		}
+		return c.fd.writeToInet4(b, &sa)
+	case syscall.AF_INET6:
+		sa, err := addrPortToSockaddrInet6(addr)
+		if err != nil {
+			return 0, err
+		}
+		return c.fd.writeToInet6(b, &sa)
+	default:
+		return 0, &AddrError{Err: "invalid address family", Addr: addr.Addr().String()}
+	}
+}
+
+func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
+	if c.fd.isConnected && addr != nil {
+		return 0, 0, ErrWriteToConnected
+	}
+	if !c.fd.isConnected && addr == nil {
+		return 0, 0, errMissingAddress
+	}
+	sa, err := addr.sockaddr(c.fd.family)
+	if err != nil {
+		return 0, 0, err
+	}
+	return c.fd.writeMsg(b, oob, sa)
+}
+
+func (c *UDPConn) writeMsgAddrPort(b, oob []byte, addr netip.AddrPort) (n, oobn int, err error) {
+	if c.fd.isConnected && addr.IsValid() {
+		return 0, 0, ErrWriteToConnected
+	}
+	if !c.fd.isConnected && !addr.IsValid() {
+		return 0, 0, errMissingAddress
+	}
+
+	switch c.fd.family {
+	case syscall.AF_INET:
+		sa, err := addrPortToSockaddrInet4(addr)
+		if err != nil {
+			return 0, 0, err
+		}
+		return c.fd.writeMsgInet4(b, oob, &sa)
+	case syscall.AF_INET6:
+		sa, err := addrPortToSockaddrInet6(addr)
+		if err != nil {
+			return 0, 0, err
+		}
+		return c.fd.writeMsgInet6(b, oob, &sa)
+	default:
+		return 0, 0, &AddrError{Err: "invalid address family", Addr: addr.Addr().String()}
+	}
+}
+
+func (sd *sysDialer) dialUDP(ctx context.Context, laddr, raddr *UDPAddr) (*UDPConn, error) {
+	fd, err := internetSocket(ctx, sd.network, laddr, raddr, syscall.SOCK_DGRAM, 0, "dial", sd.Dialer.Control)
+	if err != nil {
+		return nil, err
+	}
+	return newUDPConn(fd), nil
+}
+
+func (sl *sysListener) listenUDP(ctx context.Context, laddr *UDPAddr) (*UDPConn, error) {
+	fd, err := internetSocket(ctx, sl.network, laddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
+	if err != nil {
+		return nil, err
+	}
+	return newUDPConn(fd), nil
+}
+
+func (sl *sysListener) listenMulticastUDP(ctx context.Context, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
+	fd, err := internetSocket(ctx, sl.network, gaddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
+	if err != nil {
+		return nil, err
+	}
+	c := newUDPConn(fd)
+	if ip4 := gaddr.IP.To4(); ip4 != nil {
+		if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
+			c.Close()
+			return nil, err
+		}
+	} else {
+		if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
+			c.Close()
+			return nil, err
+		}
+	}
+	return c, nil
+}
+
+func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+	if ifi != nil {
+		if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
+			return err
+		}
+	}
+	if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
+		return err
+	}
+	if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
+		return err
+	}
+	return nil
+}
+
+func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+	if ifi != nil {
+		if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
+			return err
+		}
+	}
+	if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
+		return err
+	}
+	if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
+		return err
+	}
+	return nil
+}